New evidence for evolution Flashcards
(21 cards)
What did old evidence for evolution rely on?
Similarites in the apperance of living organisms and on fossil evidence
How did old evidence of evolution cause problems?
particularly when two species look similar because they evolved in response to similar niches
What gives insight to scientists into evolutionary links?
DNA profiling and Proteomics
The more differences there are in the DNA…
the longer the time since they had a common ancestor
How can we estimate how long ago that a common ancestor lived?
BY using the Mutation Rate as a molecular clock
What makes human evolution hard to follow?
Limited fossil evidence
How can scientists solve this problem of limited fossil evidence causing it to be difficult to follow along with human evolution?
Scientists can extract DNA from suitable fossils under 100,000 years old, and analyze it using the polymerase chain reaction (which amplifies minute traces of DNA) and DNA profiling
What is the three types of lice?
Head lice
Pubic lice
Body lice
What does DNA evidence suggest about humans and chimps?
that common ancestors of humans and chimps diverged about 6 million years ago, and the head lice species diverged at the same time
What did DNA analysis of the human head louse and body louse show?
This shows that they formed separate species around 70 000 years ago
Where does body lice live in?
Body lice live in close-fitting fabric
What DNA profiling show about the pubic louse?
DNA profiling shows that the pubic louse is more closely related to the gorilla louse than to other human lice
What does the biology journal show about human and gorilla ancestors and what does it suggest?
The biology journal shows that human and gorilla ancestors diverged about 6 million years ago, but that pubic and gorilla lice only diverged about 3 million years ago
This suggests that by then humans lost most of their body hair.
What is the explanation about human ancestors and pubic lice?
One explanation is that human ancestors picked up pubic lice from gorillas by using plant bedding that gorillas had slept on
What does DNA evidence from the lice suggest?
Overall, DNA evidence from the lice suggests humans had head lice with chimpanzee louse ancestors and pubic louse from gorilla louse ancestors, long before they began wearing woven clothes, and body lice evolved
What do scientists use evidence from the DNA analysis of many species for, and what does the process rely on?
Scientists use evidence from the DNA analysis of many species to help build diagrams that model the evolution of species from a common ancestor
The process relies on how data are interpreted using statistics and bioinformatics, including computer analysis
Where do scientists look for evidence to help build these diagrams from DNA analysis of species?
from studies based on appearance, behaviour or fossil data as well as the evidence from modern DNA and protein studies
What happens when a piece of research produces useful results and conclusions?
When a piece of research produces useful results and conclusions, it is submitted to a scientific journal
What happens when an article is submitted?
it goes through a process of peer review during which it is read by a number of experts to see if its reliable
Why should a paper provide enough information?
so that scientists can use it to carry out the same or similar investigations, so that conclusions can be validated
What happens at scientific conferences?
scientists working in the same field get together to discuss ideas, this will help to promote the development of new techniques in research as well as providing opportunities to challenge the validity of results that are being presented
