Aquatic Predators-Crocs-1

J. Moore (
Mon, 26 Jun 95 10:13:00 -0500

Attempts to construct theories about early human evolution must contend
with, among other things, the problem of predation and how to avoid it
(as much as possible:). When dealing with the idea of the transition
from hominoid to hominid on land, we can examine how our close
relatives, chimpanzees for instance, deal with potential predators. I
have posted on this before and will probably do so in the future when
I've had a chance to read some of the accounts of predation by leopards
(and its effects) in the heavily forested western Africa study areas.

When dealing with predation during a transitional period in the water,
we have to look at the problem squarely. The several variations of the
Aquatic Ape Theory vary in whether the transition happened in salt or
fresh water (although fresh water scenarios eliminate any possibility of
explaining salt excretion as the salt water scenarios attempt to do),
but they all agree that the transition to habitual bipedalism required a
water environment. Except for Hardy's original claims, the amount of
time actually spent in the water doesn't get discussed much, but we
would have to assume that it must have been most of the time spent in
locomotion, or we wouldn't expect bipedalism to be adopted for the
reasons the AAT suggests. These reasons are that the water would
otherwise be over the hominids' heads, and that the water would support
the weight of the hominid, lessening strain. Both these requirements of
the theory suggest that we're talking about spending many hours a day in
water that is considerably more than waist deep. This makes for an
enormous amount of exposure to common and viscious predators that would
be seldom, if ever, encountered by a land-based transitional hominid
(although they would be expected to occasionally get water from
waterholes, lakes, rivers, and streams, these land-based hominids might
reasonably be expected to more often get their water the way chimpanzees
in areas without standing water most often do).

The various accounts also make many statements about the lure of this
water environment for safety from predators. My point is that rather
than being a haven from predators, this environment would not only
expose such hominids to a great number of predators, but also predators
which seem much harder to defend oneself from. To explain this, I'll
give information about both sharks and crocodiles, which would be
expected to be the main predators of such hominids, whether in salt or
fresh water. Both crocodiles and sharks which are highly dangerous to
humans even today are to be found in both fresh and salt water in

Sir Alister Hardy, "Was there a *Homo aquaticus*?", article originally
appeared in *Zenith*, 1977, vol. 15(1):4-6.
Reprinted in 1982 *The Aquatic Ape* by Elaine Morgan, Stein and Day:
Briarcliff Manor, N.Y.

pg. 150:
So after some twenty million years or more of living a semi-aquatic
life -- I must make it clear that I do not suppose man spent more than
perhaps five or six hours in the water at a time -- *Homo aquaticus*
left the sea (or lake) a very different creature from when he first
entered it.

pg. 150:
Perhaps it was not only a shortage of food that sent man to the water
in the first place, but also a means of escaping from powerful
predators: possibly *Homo aquaticus* was only able to survive and evolve
with the help of a number of small sandy or rocky islands strectching up
the tropical coasts or margins of lakes where he could live in large
colonies, like those of seals or penguins, and where his only enemies
were sharks and killer whales in the sea or crocodiles in lakes and

1991 *The Aquatic Ape: Fact or Fiction?* Edited by Machteld Roede,
Jan Wind, John M. Patrick and Vernon Reynolds. Souvenir Press: London.

Leon P. Lumiere
Chapter 3. "The Evolution of Genus *Homo*: Where It Happened"

pg. 27:
The dwindling forest would produce exactly the environmental conditions
required by the Hardy hypothesis; those apes near the coast, losing
their forest, gradually would be forced into water to find both food and
protection from predators.

Derek Ellis
Chapter 4. "Is an Aquatic Ape Viable in Terms of Marine Ecology and
Primate Behavior?"

pg. 37:
How did apes survive on the savannah when there were fierce, fast
predators there, day and night?

pg. 67:
Escape from land-based predators, when the apes were on
shore, would be by running back to water and swimming away.


>From these quotes you can see that escape from predators is considered
to be an extremely important part of the purported aquatic transitional
environment. Note that even without considering aquatic predators, the
idea of hominids escaping land-based predators such as lions by "running
back to water and swimming away" is problematic, since lions hunting by
waterholes, streams, etc. often chase their prey into the water and kill
them there. Since human swimming speed is much slower than human
running speed, the usefulness of this method of escape seems to be an
assumption that may not hold water. But in this post I am primarily
concerned with describing the habitats and habits of water-based
predators. This post will deal with crocodiles, and a later post will
deal with sharks.

The following quotes are from:
1989 *Crocodiles and Alligators*
Various editors and contributors: Consulting Editor, Charles A. Ross
(Museum Specialist, Department of Vertebrate Zoology, National Museum of
Natural History, Smithsonian Institution, Washington, D.C., USA)
Facts on File: New York and Oxford.

My additional notes will be in brackets [] and offset by *****s.
[question: how do we know there were crocodiles in eastern Africa at the
time of the transition?]
Evolution and Biology: Evolution
Chapter by Dr. Eric Buffetaut (Director of Research, Centre National de
la Recherche Scientifique, University of Paris, France)

pp. 37-38:
The ancestry of the Nile Crocodile (*Crocodylus niloticus*) and, to some
extent, of the African Slender-snouted Crocodile (*Crocodylus
cataphractus*) is known with some precision because of abundant
crocodile fossils from the Tertiary and Pleistocene of northern and
eastern Africa.
[Okay, they were around (and had been for some millions of years), but
would crocodiles be in the sorts of habitats that the purported
aquatic hominids were in?]
Behavior and Environment: Habitats
Chapter by Dr. Angel C. Alcala (Professor of Biology and Director,
Marine Laboratory, Silliman University, Philippines) and Maria Teresa
S. Dy-Liacco (Research Assistant, Marine Laboratory, Silliman
University, Philippines)

pg. 136:
Crocodilians are amphibious vertebrates, spending part of their lives in
water and part on dry land. They inhabit rivers, lakes, ponds,
marshlands, swamplands, and estuaries.

pg. 137:
The edges of freshwater lakes and ponds, where the water is shallow,
receive abundant sunlight and therefore abound in rooted and floating
plants that in turn support a diverse fauna. These edges of lakes and
ponds, or marshes, are favorite haunts of crocodilians, since they reply
on both water and land for their activities. The still waters of the
lakes and ponds offer crocodilians a habitat that is rich in food
The lower reaches of rivers, where the water is slow moving,
relatively warm, more saline, and well-stocked with plant life, also
provide adequate cover and a good supply of food for larger aquatic
organisms, including crocodiles. Freshwater and mangrove swamps are
often well-developed in these lower reaches.
[Well, that about covers it; they were in every type of habitat
that these small hominids have been said to possibly have been in.]
continued next message...
Jim Moore (

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