Evolution
What were the elements of early earth?
Contained CO2, CO, Nitrogen, Ammonia, Methane But, No Oxygen!
What does bipedalism mean?
Walking on two legs
Describe natural selection
Results in changes in the frequency of heritable traits in a population; survival of the fittest!
As chimpanzees evolved into humans what changed over time?
Brain size INCREASED and Jaw size DECREASED
What were the first true cells?
Prokaryotes.
The ability to develop and use tools was first seen in early hominids. Which of the following characteristics was the main factor that contributed to this ability?
Bipedalism
What does molecular evidence tell us?
Two closely-related organisms will have similar DNA, RNA, and protein (amino acid) sequences.
Vertebrates all share gill slits and a tail in their early embryo stage. What does that tell us about these vertebrates?
The similarities suggest that Vertebrates descend from ancestors with genes that code for the development of tails and gill slits.
What does endosymbiosis describe?
Eukaryotic cells came from a symbiosis of prokaryotic cells
3 parts of Genetic variation
Mutations, recombination and lateral gene transfer
Originally, two species of finches lived in the Maldives. One species had long, narrow beaks for capturing insects from within trees. The other species had larger, thicker beaks for cracking seeds. Following an increase in logging, this ecosystem’s population of finches with narrow beaks began to decline. How does this event support the theory of evolution?
Its a principal of natural selection
What is adaptation?
Any characteristic or trait that increases fitness (the ability to survive & reproduce)
Describe the Miller & Urey experiment
They performed experiments to study the origins of life. They created an atmosphere rich in methane, hydrogen, ammonia, water, and simulated lightning. 10-15% of the carbon had turned into organic compounds, and 2% of the carbon had created amino acids.
What is Genetic Drift
A sudden environmental act that reduces the population size and leads to a loss of variation
Which of the following conditions are required for natural selection?
I. overproduction of offspring
II. competition for resources
III. genetic variation
IV. natural disasters
I,II, & III
What is divergent evolution and convergent evolution?
Convergent: Occurs when unrelated species occupy similar niches.
Divergent Evolution: The pattern of evolution in which species that once were similar to an ancestral species diverge, or become increasingly distinct.
We know now that DNA -> RNA -> Protein, but what sequence of events best describes the current theory of the origin of life on Earth?
RNA -> DNA -> bacteria
What is gene flow?
The movement of individuals into or out of the population and leads to a change in variation
When an organism joins a new population, its genes become part of the new population’s gene pool. How does this gene flow affect populations?
Gene flow between populations increases genetic diversity over time.
Oxygen was a toxic compound to most life forms from that time period. Today, oxygen is required by all but some of the most primitive life forms. Which statement best explains how early life forms that were harmed by oxygen evolved into today's life forms that require it?
Over time, many species gradually adapted to a more oxygen-rich environment, allowing them to survive in shallow water and on land.