True in most cases unless they erode then the younger ones will be on top
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.
Answer:
The image has your answer :)
Explanation:
Answer:
The correct answer will be option-B.
Explanation:
<em>Homo neanderthelensis</em> or Neanderthals are the close relatives of the <em>Homo sapiens</em> or modern humans which became extinct around 10,000 years ago.
The Neanderthals and sapiens are the two related species of the same genus Homo but they showed distinct features like Neanderthals were muscular and shorter in height compared to the <em>Homo sapiens</em>. Recent fossils indicated that Neanderthals and<em> Homo sapiens</em> interbreed in some parts of the world as they were closely related to each other.
Thus, Option-B is the correct answer.