Evolution Flashcards
The gradual process of genetic change and adaptation over successive generations, leading to the diversity of life forms observed today.
What is the significance of looking at stars on a clear night sky?
Looking at stars allows us to peer into the past, as the light we see from them started its journey millions of years ago.
How are stellar distances measured, and why does this relate to looking into the past?
Stellar distances are measured in light years. This relates to looking into the past because the light we see from stars today actually began its journey millions of years ago.
Describe the conditions of early Earth’s atmosphere.
Early Earth had no atmosphere initially. Gases like water vapor, methane, carbon dioxide, and ammonia were released from the molten mass, covering the surface.
What led to the formation of the ozone layer on early Earth?
Oxygen released from UV rays combined with ammonia and methane to form water, CO2, and other compounds, leading to the formation of the ozone layer.
When did life first appear on Earth, and how long ago was it?
Life appeared approximately 500 million years after the formation of Earth, about four billion years ago.
What is the theory of panspermia, and who proposed it?
Panspermia is the idea that life originated from outside Earth. Early Greek thinkers, including Oparin and Haldane, proposed this theory.
What did Louis Pasteur’s experiments disprove?
Louis Pasteur’s experiments disproved the theory of spontaneous generation, showing that life arises only from pre-existing life.
How did Oparin and Haldane propose the first life forms might have originated?
Oparin and Haldane proposed that the first life forms could have come from pre-existing non-living organic molecules through chemical evolution.
What conditions were present on early Earth according to Oparin and Haldane?
Oparin and Haldane suggested that early Earth had high temperature, volcanic storms, and a reducing atmosphere containing gases like CH4 and NH3.
What experiment did S.L. Miller conduct, and what were the results?
S.L. Miller conducted an experiment simulating early Earth conditions, observing the formation of amino acids from gases like CH4, H2, NH3, and water vapor.
What evidence supports the idea of chemical evolution?
Analysis of meteorite content and laboratory experiments like Miller’s have shown the formation of organic compounds, supporting the idea of chemical evolution.
When did the first non-cellular forms of life likely originate?
The first non-cellular forms of life likely originated around 3 billion years ago as giant molecules such as RNA, proteins, and polysaccharides.
When did the first cellular forms of life possibly originate?
The first cellular forms of life possibly originated around 2 billion years ago.
What environment did all life forms exist in initially?
All life forms initially existed in a water environment.
What is the accepted theory for the origin of life by the majority?
The accepted theory is that life arose slowly through evolutionary forces from non-living molecules in a process called biogenesis.
What theory does conventional religious literature propose about the origin of living organisms?
Special creation theory posits that all living organisms were created as they are, that biodiversity has remained constant since creation, and that the Earth is approximately 4000 years old.
What observations did Charles Darwin make during his voyage on the H.M.S. Beagle?
Darwin observed that existing living forms share similarities not only among themselves but also with life forms that existed millions of years ago, many of which are now extinct.
What did Darwin conclude from his observations?
Darwin concluded that there has been gradual evolution of life forms, with populations exhibiting built-in variation in characteristics. Natural selection favors characteristics that enhance survival in specific environments, leading to the survival and reproduction of individuals better suited to their surroundings.
What does the term “fitness” refer to according to Darwin?
Fitness, according to Darwin, refers ultimately and solely to reproductive fitness. Individuals better suited to their environment leave more offspring, thereby passing on their advantageous traits.
What mechanism did Darwin propose for evolution?
Darwin proposed natural selection as the mechanism for evolution, wherein individuals with advantageous traits are more likely to survive and reproduce, passing on those traits to future generations.
Who else came to similar conclusions about evolution around the same time as Darwin?
Alfred Wallace, a naturalist who worked in the Malay Archipelago, independently arrived at similar conclusions about evolution through natural selection around the same time as Darwin.
What conclusion can be drawn about the age of the Earth based on geological and biological history?
The Earth is much older than previously thought, likely billions of years old, as evidenced by the correlation between geological and biological history.
What is paleontological evidence of evolution?
Paleontological evidence of evolution includes fossils found in different-aged rock sediments, indicating the existence of various life forms over geological timespans.
How are the ages of fossils calculated?
The ages of fossils are calculated using radioactive dating methods, which rely on the decay of radioactive isotopes within the fossils to determine their age relative to other geological layers.
