HOMINID EVOLUTION
Introduction
The order of animals known as primates includes the prosimians (lemurs, bush babies,
etc.), monkeys, apes (chimps, gorillas, etc.), and hominids (bipedal primates including humans).
Fossil and molecular evidence indicates that apes and hominids shared a common ancestor
around seven million years ago.
Since the time of their divergence from apes there have been
many hominid species that coexisted on Earth.
However, there is currently only one species left
–
Homo sapiens
(man).
This lab exercise will give you the opportunity to examine replicas of some of the most
important fossil hominid skulls that have been found.
As part of this exercise you will compare
the characteristics found on these skulls to those of modern humans and apes.
Finally, you will
analyze your data and determine which features of extinct hominids are more similar to modern
humans and which ones appear more like those found in apes.
Procedure
1.
Hominid and ape skulls will be located at stations spread around the laboratory.
2.
Each lab group will be given a ruler, a meter stick, and a pair of calipers.
3.
Each group will rotate through each station and collect data from each skull.
4.
DO NOT copy data from other groups, or split your group between stations.
5.
While at each station, groups will collect data on 14 different skull traits.
Data will
be recorded in Table 1.
6.
After data is collected for all skulls, each group will summarize the trends in modern
apes and humans by completing the first two columns of Table 2.
Then in the shaded
columns of Table 2, write an “A” for ape-like or an “H” for human-like, based on
whether the fossil hominid skull traits are closer to those of modern apes or humans.
7.
Add the total number of ape-like and human-like traits in each fossil skull.
8.
The approximate age of each fossil is given in the table below.
9.
Students will form conclusions about the relationship between the age of the fossil
and its similarity to modern primates.
The skulls used in this experiment include:
Pan troglodytes
(chimpanzee)
Current
Homo sapiens
(modern human)
Current
Fossil Skulls
Homo sapiens
(Cro-Magnon man)
10,000-30,000 yrs.
Homo neanderthalensis
(Neanderthal man)
30,000 yrs.
Homo heidelbergensis
(Heidelberg man)
300,000 yrs.
Homo erectus
(Peking or Java man)
400,000-500000 yrs.
Homo habilis
(“Handy” man)
1,900,000 yrs.
Australopithecus boisei
(robust early homind)
1,800,000 yrs.
Australopithecus afarensis
(gracile early hominid)
2,900,000-3,600,000 yrs
