The World's only Snorkelling Animal

[sross]

Couldn't resist posting up links to these videos of Indian elephants who swim quite well in the open ocean, and they use their trunk as a snorkel!

Rajan the swimming elephant of India's Andaman Islands, is now 65 years old and is the last of a group of elephants that worked on logging operations back in the years before logging was banned in the archipelago. The animals were trained to swim in the ocean and actually swam on occasion between neigbouring islands to different logging sites.

[ame=http://www.youtube.com/watch?v=Hh1am2-wElc]YouTube - Elephant Swimming, Andaman Islands, India[/ame]

[ame=http://www.youtube.com/watch?v=guACeVYUp7M]YouTube - Swimming elephant[/ame]

and here's David Attenborough going out for a swim with one of these guys, and proposing the "Aquatic Elephant Theory"

[ame=http://www.youtube.com/watch?v=N8xExiqpeeQ]YouTube - Attenborough Rides an Elephant[/ame]

 

[devondave]

Great vid's.
Rajan was featured in a diving magazine.
No longer logging, he earns his keep by snorkeling with paying divers.
I think it's mainly for the logbook tick-
Time in . . . Time out . . .
Air used . . .
Max Depth . . .
Vis' . . .
Notes- SAW ELEPHANT!!

 

[Siku]

Aquatic mammal anyone? Elaine Morgan talks about elephants at length in The Descent of Women - webbed feet, hairlessness, and other adatations I've forgotten now. Interstingly they seem to have done it missionary style at some point in the past (an aquatic mammal trait according to Ms Morgan), then reverted to the more bestial approach. The legacy of these adaptaions is in the winding route to the womb in the lady elephant!

 

[wet]

Elephant closest living relative: manatee-dugong

Heres a mountain monkey that needs a mask in the rain:
New Snub-Nosed Monkey Discovered In Myanmar - Science News - redOrbit

Funny it sneezes in rain, while some humans sneeze in sunlight.

 

[sross]

Hah, elephants have been responsible for more underwater developments than you can imagine

 

[wet]

At about 39 million years old, the primates from Libya would have been roughly contemporaneous with Biretia from Algeria, and the abundance of large, semi-aquatic, early elephants such as Barytherium and Moeritherium may indicate an environment similar to the slightly geologically younger primate sites of Fayum, Egypt.

Ancient anthropoids & aquatic elephants
http://www.wired.com/wiredscience/2...t-at-an-asian-origin-for-anthropoid-primates/

Pleistocene mammoths and elephant relatives
http://www.wired.com/wiredscience/2010/10/exhibit-review-mammoths-and-mastodons/

OT to thread title but related to human backfloating/snorkeling nose (protruding & hooded):
from Jon Cohens' Almost Chimpanzee book

Matsuzawa et al - infant apes larynx drop (parallel to small lar. air sac development in all apes, later modifed in humans due to diving/backfloating?)...mother chimps don't teach infants how to use anvils to break oil palm nuts, the young learn via trial and error with slight assistance only.... from page 168: 'researchers also have documented the chimps using several other types of tools including folding leaves to scoop water, fashioning a wand from a grass stem to retrieve algae from a pond, dipping a stick into honey or ant nests, using a pestle to pound the crown of an oil palm tree to extract heart of palm'....("algae"? could it be floating hydrocharis? (ndoki gorilla raking hydrocharis at pond surface with open hands)... chimp infants communicate by imitation like human infants...human infants don't cling (though fingers can), monkeys don't have mutual gaze but chimps and humans do (mother-infant), chimps have serial birth (every 5 years) humans have near-parallel (every year) birth because larger group societies - collaboration so babies cry more than chimp infants who are always with them at night...chimps and orangutan infants must lift contralateral limbs to stabilize when lying on back, so must grasp, humans don't (backfloating past?) but can communicate while supine...

 

[wet]

DO MARINE MAMMALS HAVE A UNIQUE TYPE OF MEIBOMIAN GLAND?
Nadja Knop, Erich Knop, Robin Kelleher Davis

['Tears in elephants, manatees & hyraxes (hoofed "squirrels")' indicate semi-aquatic shared origin. IMO the LCA (last common ancestor) was very beaver-like, when it speciated the gnawing incisors became tusks and the nose form diverged.]

During the course of vertebrate evolution, the naso-lacrimal system is
believed to be developed among the first animals to become terrestrial.
In doing so, the anterior portion of the eyes of these "land invaders" were
kept moistened so as to maintain corneal clarity as well as provide
protection against potential microbial pathogens.
The naso-lacrimal system of the Florida manatee & other paenungulates
(Hyracoidea, Proboscidea, Sirenia) have been little understood.
We have discovered that Elephas maximus, Procavia capensis & Trichecus
manatus do not form the traditional naso-lacrimal system : they lack
lacrimal glands, lacrimal punctae, naso-lacrimal ducts & the tarsal glands
(Meibomian glands).
Instead, they possess unusual naso-lacrimal systems not previously
encountered among mammalian sp) or other vertebrates for that matter.

The present study primarily involves anatomical examination of the
naso-lacrimal systems associated with the paenunugulate eye.
... To date, the evidence for the close phylogenetic relationship of the

Sirenia, Proboscidea & Hyracoidea (Paenungulata) consists of a combination
of similiarities across a wide breadth of characteristics (eg, hemoglobin
sequences, lens protein construction, mitochondrial rRNA sequences, dental,
taxepodial & other skeletal features).
In spite of the variety of supporting findings, some of the morphological
features have been questioned or refuted as being primitive or convergent.
In the present study, the lack of traditional nasolacrimal systems in the
Florida manatee, Asian elephant & rock hyrax strongly supports their common
evolutionary origin.
The absence of the lacrimal gland among terrestrial vertebrate spp is rare
(snakes), esp.among mammals.
Its agenesis among humans is an extremely rare mutative event that involves
a concomitant loss of salivary glands, but not a loss of the drainage puncta
or other orbital glands.
The loss of both lacrimal & tarsal glands as well as those components for
tear drainage strongly suggests that the Paenungulata shared an aquatic
past.
Fairly recently, embryological development of the renal, respiratory & male
reproductive systems indicated that the elephant evolved originally from an
aquatic or semi-aquatic ancestor.
Comparable ontogenetic findings have yet to be made in the hyrax.
Among non-mammals, the presence of sebaceous glands within the nictitating
membrane is common.
However, among mammals, the Harderian gland becomes much more lacrimal in
function, losing its sebaceous nature largely due to the formation of
Meibomian glands.
The different ways that sebum-forming glands were reformed so that an oily
layer is able to cover the sero-mucous portion of tears of the Asian
elephant & the rock hyrax most likely are the result of the different
ecological pressures encountered during their subsequent evolution.
A series of articles are presently being submitted to a variety of journals
that detail the unique features of the re-evolved naso-lacrimal systems of
the 3 distantly related spp & their shared past.

Samuelson DA, Reppas G, Lewis PA, Valle C & Isaza R 2007
The loss of the classic nasolacrimal system in the Florida manatee and other
selected paenungulate species
Intern.Assoc.Aquat.Anim.Med.38th Ann.Conf.71-72

Samuelson DA, Reppas G, Wong M., Lewis PA, Barrie KP & Graham AR 2007
Re-invented nasolacrimal system among selected subungulate species
Invest.Ophthalmol.Vis Sci.(ARVO Suppl.) 47:S1214
-
Aquatic voles have meibomian glands for both aquatic and wet soil burrowing
The Meibomian Glands of Voles and Lemmings (Microtinae)
Wilbur B Quay 1954 Ann Arbor Univ Michigan Press

...

The aquatic genera Neofiber & Ondatra show several interesting parallels in
their tarsal glands.
1) The large tarsal glands are crowded and tend to be fused at the posterior
angle of the eyelids.
2) Over most of the length of the eyelids there are only small filiform
tarsal glands, similar to those seen in squirrels.
3) The enlarged tarsal glands are compacted together and do not follow the
duct of the exorbital lacrimal gland posteriorly.
In these characteristics, Ondatra is more advanced than Neofiber, since the
crowding & fusing of the enlarged glands is more extensive, and since there
are fewer of the filiform glands.

Conclusion

Study of 350 whole mounts of eyelids & their Meibomian glands from 14
microtine genera & 47 spp demonstrates:
1. Variations in Meibomian gland number cannot be correlated with sex,
season or age.
2. The number of Meibomian glands present & their morphology & location are
species characteristics.
3. Within microtines, a reduction in gland number occurs along with an
increase in the size of the remaining glands, esp.the most posterior ones,
which extend beyond the region of the eyelids as extra-palpebral glands.
4. The reduction in gland number occurs nearly equally in upper & lower lids
& primarily in their mid-region.
5. The trends in Meibomian gland number & morphology parallel in many
instances the currently accepted phylogeny of the subfamily.
Thus, the primitive genera have glands which are more numerous, smaller &
more nearly equal in size than do the more advanced genera.
6. One possible explanation for the reduction in gland number & increase in
gland size is that fossorial habits in the subfamily have been associated
with reduction in eye & eyelid size & with an increased need for secretory
protection of the eye.
7. The glandular morphology of the aquatic genera Neofiber & Ondatra is
strikingly similar, and is more advanced in the latter.

_____

Our (human) eyes are protected by a 3-layered covering:
- mucus next to the eye,
- a broad watery layer between,
- a sebaceous layer at the outside (Meibom).
Our Meibomian glands (sebum secreting) must have been adapted to our aquatic
lifestyle (salt vs freshwater?), but I lack comparisons with other primates.

--marc @ AAT group
-

Human ancestors were not soil burrowers, so aquatic foraging seems most parsimonious for the human condition.

 

[wet]

(Didn't intend to focus on this, but interesting data)
-
meibum = sebum-like secretion of Meibomius glands

Understanding and Analyzing Meibomian Lipids - A Review
IA Butovich, TJ Millar & BM Ham 2009
Curr Eye Res 33:405*420 doi 10.1080/02713680802018419

...
Function & anatomy of meibomian glands are briefly covered, giving insight
into possible mechanisms for secretory controls.
Anatomically, some anomalies in meibomian gland distribution of different
spp are presented, eg, whales vs dolphins, some marsupials.
In attempting to make the literature more accessible, lipid structure &
nomenclature are described ; these structures are related to their possible
effects on the physico-chemical properties of meibomian lipids.
The (dis)advantages of various collection & storage techniques are
described, as well as how gas chromatography & combined HPLC & mass
spectrometry coupled with fragmentation are currently enabling us to
determine the nature of the lipids in very small samples.

This review extends to discussing the lipids in tears (as opposed to
meibomian gland lipids) ; it briefly highlights new thoughts about the
interactions between proteins of the tear film & meibomian lipids.
A model that includes proteins in the outer layer of the tear film is also
presented ...

______


The Meibomian puzzle: combining pieces together
IA Butovich 2009 Prog Retin Eye Res 28:483-498

... Human meibum was shown to be a very complex mixture of lipids of various
classes. For decades, their exact structures have remained elusive because
of the limitations of the then-current techniques ... Modern techniques help
in solving this puzzle ...
The most intriguing development is the virtual absence in meibum of typical
phospholipids - an important group of amphiphilic compounds, whose role in
the human tear film was thought to be to stabilize the entire tear film
structure.
Instead, another group of previously unidentified compounds, very long chain
(O-acyl)-omega-hydroxy fatty acids, appears to be a stabilizing factor which
might be related to tear film stability & deterioration.
Thus, these compounds may become an important target in biochemistry &
(patho)physiology of ocular surface & dry eye research.

 

[ReefTroll]

Don't you need two people for further discussion Wet buddy?

Also, I thought I was a snorkelling animal.
I'm off to get re-classified.

 

[wet]

[ame=http://en.wikipedia.org/wiki/Meibomian_gland]Meibomian gland - Wikipedia, the free encyclopedia[/ame]

 

[wet]

Infant elephants are unable to use their trunks functionally, they don't seem to know what the trunk is for...

Infant manatees are unable to use their flat tails for propulsion, they use their (hand/forelimb) fins for propulsion, they don't seem to know what the tail is for...

Both the trunk and flat tail are "evolutionarily recently modified" appendages used in novel ways. Human infants parallel this slow developmental use of the body, very different from typical mammals, almost super-altricial, outside of the water.
OT: The most important human adaptation: childhood culture learning
http://scienceblogs.com/gregladen/2010/10/what_is_the_most_important_hum.php

 

[wet]

JZ Metcalfe, FJ Longstaffe, GD Zazula 2010
Palaeogeography, Palaeoclimatology, Palaeoecology 298:257-270
Nursing, weaning & tooth development in wooly mammoths from Old Crow, Yukon,
Canada: implications for Pleistocene extinctions

This study investigates differences in the δ13Ccol, δ15N, δ13Csc, δ18Osc,
Sr/Ca & Ba/Ca values of juvenile & adult Mammuthus primigenius : nursing in
woolly mammoths lasted at least 3 years, and was associated with minimal
decreases in δ13Ccol (~0.2 ‰), large decreases in δ13Csc (~1.5 ‰) & large
increases in δ15N (~2 ‰) & δ18Osc (~2 ‰) values.
Sr/Ca & Ba/Ca ratios suggest that woolly mammoth juveniles began consuming
plant foods between 2 & 3 "African Elephant Years" of age, much later than
the initiation of weaning in modern elephants.
We hypothesize that delayed weaning was an adaptation to increased predation
risk & decreased food quality/quantity during the extended hours of darkness
that occur in winter at high latitudes.
Prolonged nursing & delayed weaning may have made mammoths particularly
vulnerable to climatic stressors or human hunting.
(cold water & ice = less aquatic foraging = later weaning?)

 

[wet]

Genes separate Africa's elephant herds

Genetic work reveals forest and savanna pachyderms as distinct species.
Genes Separate Africa?s Elephant Herds - Science News
%E2%80%99s_elephant_herds
Tina Hesman Saey 21.12.10
- Science News
Africa's forest & savanna elephants are 2 distinct spp, a new genetic study
shows. Forest elephants are smaller than savanna elephants and have rounder
smaller ears & straighter thinner tusks.
African elephants have new distant cousins ‹ other African elephants.

A genetic analysis of elephants & their extinct relatives, woolly mammoths &
mastodons, shows that forest-dwelling African elephants are a separate
species from Africa's savanna elephants. The research (PLoS Biology) "does a
very thorough job of nailing shut the coffin on some of the more heretical
theories" about elephant evolution, says Stephen O'Brien (not involved in
the research).

Forest elephants make up only about a quarter of 500,000 or so of the
elephants living in Africa today. Poaching & habitat destruction have caused
already endangered populations to dwindle, but the new finding could spur
conservation efforts to protect the animals.

Forest & savanna elephants evolved into different spp from a common ancestor
between 2.6 & 5.6 Ma, the new analysis reveals. That's about the same time
as Asian elephants & woolly mammoths came to a fork in their family trees.
Asian elephants & mammoths' many differences mean that some not only
consider the animals distinct spp but different genera ‹ another level of
taxonomic hierarchy.

David Reich (co-author): "If you believe that the mammoth & the Asian
elephant are different spp, then it's very difficult to argue that the
forest & savanna elephants aren't separate species."

Nevertheless, people have been debating whether the big savanna elephants &
smaller forest elephants belong to 1 or 2 spp for a very long time. Alfred
Roca (co-author: "This has been an ongoing debate since before genetics
began." The 2 pachyderms look different, but sometimes come together &
breed, producing hybrids. Hybrid males are sterile, but females can breed.

DNA evidence has also been controversial. Previously, researchers have
examined elephant mtDNA. Those studies seemed to indicate that forest &
savanna elephants have interbred, suggesting that they are not separate spp.

But mtDNA gives clues only about female ancestry. To get the entire picture
of genetic history, researchers needed to examine DNA from the cell nucleus,
where the vast majority of genes are stored.

In the new study, researchers compared nuclear DNA from living elephants as
well as from a 43-ka woolly mammoth bone from Siberia & from a 50-to-130-ka
N.American mastodon tooth ... The forest & savanna groups are at least as
different as Asian elephants & mammoths: "I've always argued that they are
very different, but that level of difference surprised me."

Forest elephants had the greatest amount of genetic diversity of all the spp
studied ; savanna elephants were the least genetically diverse. That
discrepancy could mean that the 2 spp have different social structures, says
Roca.

Only the biggest strongest savanna males get to mate with females: "So you
lose the genetic diversity in the other males." Forest elephants' high
diversity could mean that males aren't as competitive with each other and
more males get access to females, he says. Mammoths also had rel.low
genetic diversity, suggesting that mammoth males were also highly
competitive.

Asian elephants may have been responsible for keeping the forest & savanna
elephants apart long enough to become separate spp. All elephants
originated in Africa, and some Asian elephants migrated out of the continent
at about the same time as humans did c 200 ka. The remaining Asian
elephants in Africa were wiped out c 35 ka ago under still mysterious
circumstances, Roca says.

Until that time, Asian elephants were the dominant elephant spp in Africa
and may have kept the other 2 groups separated, O'Brien says: "They couldn't
move around because the continent was full of these big Asian elephants that
didn't like them" ...
-

Note that savanna animals typically have long narrow ears, arboreal animals typically have more smaller rounded ears. True in elephants and monkeys, etc.

 

[wet]

Another snorkeling link: Neandertals, with their big noses, did not become big-nosed due to cold, to 'warm the air before it entered the lungs'. More likely, the nose developed in association with diving and backfloating, functioning as a hydrodynamic snorkel (see convergent parallels in sea otter and blue whale).

Journal of Human Evolution doi 10.1016/j.jhevol.2010.10.003
The Neanderthal face is not cold adapted
TC Rae, T Koppe & CB Stringer 2010

Many morphological features of Hn, including the reputed large size of its paranasal sinuses, have been interpreted as adaptations to extreme cold, as some Hn lived in Europe during glacial periods. This interpretation of sinus
evolution rests on 2 assumptions:
1) that increased cranio-facial pneumatization is an adaptation to lower ambient temperatures,
2) that Neanderthals have rel.large sinuses.
Analysis of humans, other primates & rodents, however, suggests that the 1st assumption is suspect; at least the maxillary sinus undergoes a significant reduction in volume in extreme cold, in both wild & laboratory conditions.
The 2d assumption (that Hn sinuses are large, extensive or even hyper-pneumatized) has held sway since the first specimen was described, and has been interpreted as the causal explanation for some of the distinctive aspects of Hn facial form, but has never been evaluated with respect to scaling.
To test the latter assumption, previously published measurements from 2D
X-rays & new 3D CT data of Hn & temperate-climate European Hs are regressed against cranial size to determine the relative size of their sinuses.
- The 2D data reveal a degree of cranio-facial pneumatization in Hn that is
both commensurate with the size of the cranium & comparable in scale with
that seen in temperate climate Hs.
- The 3D analysis of CT data from a smaller sample supports this conclusion.
These results suggest that the distinctive Hn face cannot be interpreted as
a direct result of increased pneumatization, nor is it likely to be an
adaptation to resist cold stress; an alternative explanation is thus
required.

 

[Mr. X]

Another snorkeling link: Neandertals, with their big noses, did not become big-nosed due to cold, to 'warm the air before it entered the lungs'. More likely, the nose developed in association with diving and backfloating, functioning as a hydrodynamic snorkel (see convergent parallels in sea otter and blue whale).
.

What a strange thread! So does that also suggest that humans with big noses have evolved them while "diving and backfloating, functioning as hydrodynamic snorkel"? Love it - as they say "noses run in my family". But it does sound like complete tosh, think about it: if you lay on your back, the bottom of your nose, not the tip will determine when the water enters. From limited personal experience, I know that some nose shapes/sizes block more easily than others, dangerously so in some cases - that would seem like a simpler, more rational explanation to me. Whatever happened to Occams's razor? But how do you explain why so many people have small or flat noses? Doesn't the common existence of both large and small noses (in hot and cold climates, by sea and in land) suggest that neither provides a significant evolutionary advantage?

 

[Mr. X]

Don't you need two people for further discussion Wet buddy?

Also, I thought I was a snorkelling animal.
I'm off to get re-classified.

Not if you have multiple personalities.

Yes, most of the forum members are snorkeling animals/mammals.

Hopefully this thread now has more than enough information on elephant snorkeling to meet the needs of all members, and then some.

 

[wet]

What a strange thread! So does that also suggest that humans with big noses have evolved them while "diving and backfloating, functioning as hydrodynamic snorkel"? Love it - as they say "noses run in my family". But it does sound like complete tosh, think about it: if you lay on your back, the bottom of your nose, not the tip will determine when the water enters. From limited personal experience, I know that some nose shapes/sizes block more easily than others, dangerously so in some cases - that would seem like a simpler, more rational explanation to me. Whatever happened to Occams's razor? But how do you explain why so many people have small or flat noses? Doesn't the common existence of both large and small noses (in hot and cold climates, by sea and in land) suggest that neither provides a significant evolutionary advantage?

-

Many mammals have noses which extend forward from the face, elephants the most exemplarly so. Today humans (Homo sapiens sapiens, boat using) have a wide variety of nose shapes and sizes, however I'm speaking of the general common condition of littoral-based archaic humans (Homo heidelbergensis, Homo erectus, Homo neandertalensis, etc.) from +1 million years ago until 30,000 years ago.

 

[ReefTroll]

Another snorkeling link: Neandertals, with their big noses, did not become big-nosed due to cold, to 'warm the air before it entered the lungs'. More likely, the nose developed in association with diving and backfloating, functioning as a hydrodynamic snorkel (see convergent parallels in sea otter and blue whale).

Journal of Human Evolution doi 10.1016/j.jhevol.2010.10.003
The Neanderthal face is not cold adapted
TC Rae, T Koppe & CB Stringer 2010

So what you're saying is that human evolution owes a lot to neanderthals noses etc etc?
I would HARDLY trust a source that lays claims to this sort of nonsense. Especially when this source still claims in 2010 that we as humans evolved from Neanderthals, when that has already been disproven....

 

[wet]

So what you're saying is that human evolution owes a lot to neanderthals noses etc etc?
I would HARDLY trust a source that lays claims to this sort of nonsense. Especially when this source still claims in 2010 that we as humans evolved from Neanderthals, when that has already been disproven....

The last common ancestor of modern humans and neandertals had a big nose, as did many other archaic humans now extinct, such as Homo erectus and Homo heidelbergensis, the enlarged nose most likely due to part-time combined forage-diving/backfloating over millions of years living along shorelines. When diving/backfloating became less significant to human survival (due to earliest boats, nets, dryland foraging) the nose form changed in different populations via selection for local conditions.

Most people (those descended from Out-Of-Africa group 2) have a very small amount of DNA which came from Neandertal ancestors. People from Congo & West Africa lack this Neanderthal DNA.
http://www.time.com/time/health/article/0,8599,1987568,00.html

There is another ancestral DNA found in Melanesia/Papua island people, not in anyone else, that is shared with ancient human fossils in Denisova cave, Siberia (I think Denisovans originated in the Yangtze basin and expanded outwards, coming in contact with Hss from Africa).

"The most significant finding in the paper is the demonstration that some living humans trace significant fraction of their ancestry to the population represented by the Denisova genome. As in the case of Neanderthals, different human populations show significantly different levels of similarity to the Denisova sequence. For Neanderthals, the similarities indicated between one and four percent Neanderthal ancestry for living people outside of Africa. In the case of the Denisova sequence, the greatest similarities are with living people in Melanesia – in this paper, represented by genome samples from Papua New Guinea and Bougainville. The similarities are consistent with approximately 4% contribution of a Denisova-like population to the ancestry of these living Melanesians. The paper estimates that together, the Denisova and Neanderthal-derived genes account for 8% of the ancestry of these living people." http://johnhawks.net/weblog/
http://sexyarchaeology.wordpress.co...enome-of-a-previously-unknown-human-relative/

 

[wet]

... if you lay on your back, the bottom of your nose, not the tip will determine when the water enters.

Tilt your head back further. The hooded protruding nose and upper lip keep out water (except waves), the (archaic human's dense) occiput helped to keep the "blowholes" vertical.

From limited personal experience, I know that some nose shapes/sizes block more easily than others, dangerously so in some cases - that would seem like a simpler, more rational explanation to me.

What is the explanation? Long noses produce blockage, or vice versa?

Whatever happened to Occams's razor? But how do you explain why so many people have small or flat noses? Doesn't the common existence of both large and small noses (in hot and cold climates, by sea and in land) suggest that neither provides a significant evolutionary advantage?

Early boats, nets, increased dryland foraging changed the post-aquatic typical nose shape from generallized hydrodynamic to localised dryland forms.