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:
Decrease
Explanation:
The carbon footprint is <u>the amount of carbon (in terms of greenhouse gases) being emitted by human activities</u>. In a situation where <u>social distancing is encouraged, human activity would reduce significantly</u>. Very few people will be outside and the causative agents of pollution (anthropogenic) will be significantly reduced. Further, nature would be able to minimize the impacts of pollution when human activities are less than the threshold capacity.
Let's take an example of coronavirus spread globally this year. The social distancing of 2 meters has significantly reduced the number of people going outside. Ultimately, there are fewer automobiles on the roads and a few industries are running. The result is that the air quality index has been significantly improved. For example, in India, people from 300 km away, can see the Himalayan mountain range very clearly (see image attached). This has not happened in decades after modern industrialization.
Through the umbilical vein.
The tenth day because its half of 20
brainliest?
Answer:
Ethical concerns about the development and use of biotechnology include all of the following except <em><u>concern about the development of new weapons.</u></em>
