"My question is about the pictures taken on mars. Why does NASA change the coloring throughout the pictures to make them look red?"
-
Question
How is mitochondrial DNA different from chromosomal DNA?
While chromosomal DNA and mitochondrial DNA are indeed distinct, both accumulate random mutations over time, and these changes can serve as a measure of time and thus evolutionary distances. However, the mitochondrial clock ticks about 10 times faster than the chromosomal clock. Therefore, it is suitable for tracking fairly recent events (thousands of years rather than millions). In addition, mitochondrial DNA is easier to trace because in vertebrates, mitochondria are of maternal origin and not subject to sexual recombination. In a study done at NASA’s Ames Research Center, mitochondrial DNA seem to indicate that the eukaryotic cell arose not as a result of fusion of two prokaryotes (endosymbiosis), but rather first evolved independently of each other. However, this research also suggested that mitochondria and chloroplasts were of endosymbiotic bacterial origin. Just as you guessed, mitochondria research is key in furthering our understanding of the evolution of life on Earth. For more information on the research mentioned above, see http://astrobiology.arc.nasa.gov/workshop/speakers/pace/pace_abstract.html
May 1, 2002
- How frequently are questions answered?
- I asked a question but there was no answer?
- Who is the Astrobiologist answering these questions?
- Will I get an email when my question is answered?
- What college courses should I take to become an astrobiologist?
- How can I get a job as an astrobiologist at NASA?
- Have aliens visited Earth? Are UFOs real?
- Is there a planet or brown dwarf called Nibiru or Eris that is approaching the Earth and threatening our planet with widespread destruction?
- Is it true that the Sun will be in the center of the Milky Way Galaxy in December 2012 and that this will cause a pole shift and massive destruction.
- Has NASA discovered life on other worlds?
- Astrobiology Career Path Suggestions