EARLY HOMINIDS: PREY OR PREDATORS?

Abstract

Early hominids in the past were susceptible to attack, rather than strong and fearless hominids. This is according to new fossil evidence that larger animals preyed on early hominids in the past (1). Approximately 6 percent to 10 percent of early humans were preyed upon; this is due to teeth marks found on bones made by sabre-toothed cat fangs (1).

However, the teeth of Australopithecus africanus fossils were subjected to isotopic analysis where different types isotopes of a particular atom exist in the environment in a specific ratio to each other (2, Sponheimer and Lee-Thorp, 1999). Sponheimer and Lee-Thorp, (1999) concluded in their report that isotopic analysis coded, that eating meat in the past was also part of A. africanus diet, and not only fit for eating grasses and sedges (2). However, Sussman and Hart suggest the tooth structure of A. afarensis wasn't fit for meat, but rather fit for eating fruits and nuts (1).

Effects of predation have also now been theorized as one of the major factors that contributed to the evolution of hominids (Isbell, 2005). Isbell (2005) suggest that "modern primates, behaviours such as active defence, concealment, vigilance, flight, and alarm calls have been recognized to the selective pressures of predation". Therefore it is clear that primates, like other animals, have evolved ways to minimize their risk of predation (Isbell, 2005). This is also true according to Professor Sussman, in which he states that "one of the main defences used by early hominids were to live in groups" (1). These factors such as predator avoidance also forced hominids to evolve adaptive strategies for survival. Adaptive strategies of early hominids involved; assemblage of individuals, an increase in survival strategies and being informative (1). It is now thought that predation has had an important ecological and evolutionary effects on primates as prey (Isbell, 2005).

Unfortunately the early hunting hypothesis states that early human ancestors were hunters and scavengers and possessed a killer instinct.
The debate whether early hominids were prey or predators is very difficult, because there are no direct evidence about the evolutionary effects of predation on early hominids (Isbell, 2005) even though, new fossil evidence suggests that predation was one of the factors that contributed to hominid evolution. Therefore, early hominids in the past were frail and feeble, but tend to use skills like sociability and defences to continue their existence (1).

Reference:

1. http://news-info.wustl.edu/news/page/normal/6584.html

2. http://news.bbc.co.uk/1/hi/sci/tech/255725.stm

M. Sponheimer and J.A. Lee-Thorp (1999). Isotopic evidence for the diet of an early hominid, Australopithecus africanus. Science 283: 368.

Isbell, L.A. (2005) Predation on primates: Ecological patterns and evolutionary consequences. Evolutionary Anthropology.Vol 3, Issue 2, 61-71

 

Riaan Cedras Brinley
Department of Biodiversity and Conservation Biolgy
University of the Western Cape
Private BagX17
Email: 2320648@uwc.ac.za
Ph: 0723652003
www.dj_CD.iblog.co.za