Vitaim b1. was the found in 1910
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.
All the spheres interact with other spheres. For example, rain (hydrosphere) falls from clouds in the atmosphere to the lithosphere and forms streams and rivers that provide drinking water for wildlife and humans as well as water for plant growth (biosphere).
I believe the answer is receptor sites, but correct me if I'm wrong.
Hope this helps!
<u>Distress vocalizations</u> can help this rescue dog and firefighters find fearful people and pets stuck in buildings that are on fire
Distress vocalizations are sounds produced in the presence of painful, stressful, or threatening stimuli.
Mammalian vocalizations are the product of respiratory and laryngeal activities under the direct control of brain stem cranial and spinal motor neurons and modulated by higher brain processes.
Vocalizations offer the further promise of unique informational content about the emotional state of the subject. There is evidence that the form, contexts, and neural processes which modulate distress vocalizations are highly conserved between species.
To learn more about Distress vocalizations, here
brainly.com/question/17089982
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