“There was once an animal that was an ancestor
to both humans and apes. But what was it like?”
By: Colin Barras
Level of difficulty: ** This is a more challenging task due to its length and subject matter so don't make it the first task you do at this level.
TEST YOURSELF
BEFORE YOU READ
QUESTIONS
1. Start reading the text and decide
which paragraphs form the introduction. Now answer the questions on this
section:
·
Charles
Darwin’s missing person’s inquiry was very difficult because…
·
Charles
Darwin set off a chain reaction when he published his theory of evolution. Step
one accepting that……….Step two was that there had to exist both ……….and………..
·
Which
of the following subtitles would fit this section: the search for the
missing link / Darwin sets the ball rolling / Opening a can of worms / In
search of LCA
2. Where does the first section of the
development start and where does it end? Now answer the questions:
·
Rephrase
the following to eliminate the pronoun: “This categorization”.
·
Huxley
based the deductions he made concerning the origins of man on….(tweak the text)
·
How
would you best replace “This” in the phrase “ This led to some very particular
ideas…”?
·
What
qualities was it assumed that LCA had that modern humans don’t have?
·
The
above qualities were believed to have led to…
·
What
subtitle would you give this section: Monkey business / Huxley explains /
Our brothers and sisters / Evolution acts in mysterious ways.
3. Where does the next section of the
development start and where does it end? Now answer the questions:
·
Early
beliefs as to who exactly LCA was seem to have had a scientific basis / a
rational basis / a superficial basis / an emotional basis.
·
What
seemingly illogical conclusion did Strauss reach concerning humans?
·
Straus
based his above opinion on the fact that…
·
What
was the significance of Sraus’ views? The realization that …
·
What
likely description of LCA did Straus make?
·
What
subtitle would best fit this section: Straus stirs the pot / Answering back
/ Many more theories / Humans and evolution.
4. Where does the next section of the
development start and where does it end? Now answer the questions:
·
How
would you replace the phrase “this uncertainty”?
·
The
return to the chimpanzee and bonobos as the human “sister species” was due to
the theory ….
·
How
did Zukerkandl reach the conclusion that humans and gorillas last shared a
common ancestor 11 million years ago? By noting both……….and…..
·
The
idea of the molecular clock gained traction thanks to….
5. Where does the next section of the
development start and where does it end? Now answer the questions:
·
The
theory that Ramapithecus was a direct human ancestor was deemed inconclusive because…
·
It
made sense that Ramapithecus didn’t resemble humans because …
·
Where,
in the remainder of this section, would you slot in the following sentence:
Huxley’s theories seem finally to have been verified scientifically
approximately 150 years after his death?
·
What
phase would you replace “This” with in
the phrase “This was not the only conclusion…”?
·
The
assumption that the home of the LCA must have been Africa is based on the fact
that….and the assumption that….
·
What
would you make the phrase “The story” more specific?
6. Where does the next section start
and where does it end? Now answer the questions:
·
What
was the conclusion that humans did not evolve from a knuckle-walking LCA based
on?
·
The
discovery of Ardi was significant because it was an early human / it moved
comfortably in trees like apes / it had some un-apelike qualities / it was
extremely primitive / it was our LCA
·
The
conclusions reached by studying Ardi were an overgeneralization because…
·
The
contention that LCA may not have been chimp-like is based on the tremendous
amount of evolution witnessed in apes / the surprising primitiveness of human
hands / the evolution of an opposable thumb in humans.
·
We
understand from this section that the idea of the chimp-like LCA has been
mostly been disappointed / discredited / disrespected/ disavowed.
·
Doubts
about when exactly the LCA lived arouse as a result of the fear that…
·
The
fact that an early relative of the gorilla has been found may indicate that the
LCA may have lived a lot later / a lot earlier / around the same time.
·
What
conclusion can be reached concerning the LCA from your reading of the text?
·
All
the different views concerning the LCA may mean that we may fail to…
WRITING TASK
Use all you
have learnt to state your views about the LCA.
Remember to support your opinions.
WE HAVE STILL NOT FOUND THE MISSING LINK BETWEEN US AND APES, KEY AND
TEACHERS’ NOTES
This fascinating account of the human story and
where we come from is an objective scientific summary of opinions thus far.
Although no definite conclusion concerning our last common ancestor is reached,
the story of the competing theories is still interesting to read. It will also
help students to learn to discuss issues they have strong views about in a
civilized manner; an important life skill.
1.
As far as “…what it looked like and how it behaved” / He didn’t know
when and where the missing party was last seen; he didn’t have photographs that
told him what the missing person looked like and he didn’t have a name to put
to the face / Humans belong to the same
family tree as all animals, a sister species and a last common ancestor/ Darwin
sets the ball rolling
2. Starts “Even before Darwin…” and
ends “… walking upright on two legs, he wrote”/ The categorization of humans as
primates / anatomical similarities between humans gorillas and chimpanzees /Adopting
living chimpanzees as stand-ins for LCA /Brachiation and knuckle walking /
Walking upright on two legs/ Monkey
business
3. Starts: “But it would be wrong to
think…” and ends “…rather than swinging between them / a superficial basis /
Humans were just not particularly evolved / Human arms, hands, legs and feet
were not as highly specialized as we might assume / that humans may have split
apart from other primates before apes evolved brachiation and knuckle-walking /LCA
could have been a relatively small bodied primate than ran a long branches
rather than swinging beneath them./ Answering back
4. Starts: This disagreement…and ends:
a direct human ancestor / The uncertainty concerning where humans slotted into
the primate evolutionary tree / of the molecular clock / the differences between human and gorilla
molecules and estimating the rate that those differences accumulate / new
fossil finds
5. Begins: Ramapithecus was
discovered…and ends… chimp and gorilla anatomy helped/ The conclusions came
exclusively from a study of the ape’s teeth (is enough because the relative
clause is non defining) / It predated the appearance of the human lineage /
After the sentence ending “close”/ The LAC’ likelihood of being more chimp like
/ Seven million years ago the European
and Asian apes had vanished; chimpanzees and humans split at the same time /
The story of who the LCA was
6. Begins: There had been murmurings…and
ends …in a bit of a quandary / On the fact that gorillas and chimpanzees
evolved knuckle walking independently / it had some un-apelike qualities / it
meant that there was a lot of parallel evolution across all apes / discredited/
the molecular clocks used to estimate when LCA lived were being read
incorrectly / a lot earlier/ there is
not yet universal agreement on the LCA / recognize the LCA when we find it
