Neanderthal Sex ■ 321Challenge Yourself
(^6) specimens have features that are intermediate
between those of Australopithecus africanus and Homo erectus and
provide an amazing record of the evolutionary shift from ancestral
hominin characteristics seen in Australopithecus fossils to more
recent ones seen in H. erectus fossils.
(a) Homo sapiens
(b) Homo neanderthalensis
(c) Homo habilis
(d) Ardipithecus ramidus
(^7) Briefly describe the key differences that distinguish
monotreme, marsupial, and eutherian mammals.
(^8) Place the following hominids in the correct order from earliest
to most recent by numbering them from 1 to 5.
a.^ archaic Homo sapiens
b.^ Australopithecus afarensis
c. modern Homo sapiens
d. Homo habilis
e. Homo erectus
Tr y Something New
(^9) You visit your local museum of natural history and come
upon an exhibit showcasing hominin fossils that date back
300,000–400,000 years ago. You notice that these fossils
have features intermediate between those of Homo erectus
and those of “anatomically modern” Homo sapiens. Who were
these fossils?
(a) archaic Homo erectus
(b) archaic Homo sapiens
(c) Homo neanderthalensis
(d) Homo habilis
For more, visit digital.wwnorton.com/bionow2 for access to:
E D q M
(^10) In 2004, scientists discovered the fossilized remains of an
extinct species they named Tiktaalik roseae. The fossil appears to
be a transitional species between (aquatic) fishes and (terrestrial)
four-legged amphibians. In what environments do you predict this
animal lived?
(^11) Give an example animal for some of the key adaptations
of chordates: (a) backbone, (b) skull, (c) amniotic egg, (d) bony
skeleton. Choose a different animal for each adaptation.
(^12) How does the fact that all ethnic groups except Africans
contain some Neanderthal DNA (1–4 percent of their DNA) support
the out-of-Africa hypothesis for the origin of modern humans
(Homo sapiens)?
Leveling Up
(^13) Write Now biology: if we were not alone Fossil evidence
indicates that in the relatively recent past (about 30,000 years
ago), anatomically modern humans, or Homo sapiens, may have
shared the planet with at least three other distinct hominins:
H. erectus, H. neanderthalensis, and H. floresiensis. If one or more of
these species were alive today, how would their existence affect
the world as we know it?
(^14) Is it science? Watch the original 1968 movie Planet of the Apes.
Document as many scientific problems with the movie as you can.
Which of the apes’ adaptations would be biologically possible, and
which ones would be impossible, from your understanding of apes on
Earth today? If this species did evolve to have the adaptive traits of
Homo, would its members still be called apes?