“There was once an animal that was an ancestor to both humans and apes. But what was it like?”
By: Colin Barras
Published: BBC, 18 May 2017, http://www.bbc.com/earth/story/20170517-we-have-still-not-found-the-missing-link-between-us-and-apes
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.
· Proof of evolution that you can find on your body https://www.youtube.com/watch?v=rFxu7NEoKC8
BEFORE YOU READ
· What will humans look like in the year 5000 https://www.youtube.com/watch?v=UH0hoViifJI
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…
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