1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Scrat [10]
3 years ago
9

What index provides evidence of when different types of life evolved on Earth?

Biology
1 answer:
aev [14]3 years ago
4 0

There are all sorts of ways to reconstruct the history of life on Earth. Pinning down when specific events occurred is often tricky, though. For this, biologists depend mainly on dating the rocks in which fossils are found, and by looking at the “molecular clocks” in the DNA of living organisms.

There are problems with each of these methods. The fossil record is like a movie with most of the frames cut out. Because it is so incomplete, it can be difficult to establish exactly when particular evolutionary changes happened.

Modern genetics allows scientists to measure how different species are from each other at a molecular level, and thus to estimate how much time has passed since a single lineage split into different species. Confounding factors rack up for species that are very distantly related, making the earlier dates more uncertain.

These difficulties mean that the dates in the timeline should be taken as approximate. As a general rule, they become more uncertain the further back along the geological timescale we look. Dates that are very uncertain are marked with a question mark.

You might be interested in
In three to five sentences, explain the effects of acid rain on the environment
barxatty [35]

Answer:

The ecological effects of acid rain are most clearly seen in aquatic environments, such as streams, lakes, and marshes where it can be harmful to fish and other wildlife. As it flows through the soil, acidic rain water can leach aluminum from soil clay particles and then flow into streams and lakes.

Explanation:

5 0
3 years ago
Read 2 more answers
Whodunnit?
Sauron [17]
The file above is a scam file
5 0
2 years ago
Which parts of the spectrum does chlorophyll a absorb best?
Anuta_ua [19.1K]
It doesn't absorb green light really well, but it would be blue and red light
4 0
3 years ago
Read 2 more answers
PLSSS HELP GIVING BRAINLIEST
andrew11 [14]

Answer:

A and B are your answers

Explanation:

7 0
3 years ago
Which cell structure is found in plant cells, but not in animal cells?
rewona [7]
Plant cells have a cell wall so answer 1
8 0
3 years ago
Read 2 more answers
Other questions:
  • Antipsychotic drugs have proved helpful in the treatment of:
    9·1 answer
  • Plant cells _________ have organelles that conduct photosynthesis. Photosynthesis uses the energy from sunlight to create food f
    14·2 answers
  • What kinds of bacteria are spherical
    9·2 answers
  • When people experience extreme back injuries they can lose the ability to move their bodies below a certain point. What part of
    7·1 answer
  • Dna replication is highly accurate. it results in about one mistake per billion nucleotides. for the human genome, how often wou
    9·1 answer
  • The European buckthorn was introduced to North America as an ornamental plant. However, this plant is now a major threat to many
    7·1 answer
  • What does nitrogen fixation accomplish?
    9·1 answer
  • What type of molecule "unzips" DNA to facilitate the process of replication? *
    15·1 answer
  • . <br> How does the seed of a gymnosperm differ from the seed of an angiosperm?
    8·2 answers
  • Which of the following describes proper microscope care and technique?
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!