That Trait (Hitchhiker's thumb) may be recessive in both the parents but when they transmitted their genes to their offspring, it became dominant in that 'cause of two similar genes (Homozygous Condition).
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The oldest fossils present at the bottom of rock layer whereas the youngest fossils are present in the top layer.
<h2>Rock layers from oldest to youngest</h2>
The rock layers that is located farthest from the ground surface are considered as the oldest rock layers and rock layers that are closest to the ground surface are considered as the youngest. A fossil is the remains or traces of plants and animals that lived long ago.
<h3>Presence of fossil</h3>
Those fossils which are present at the bottom of the rock layers are considered as the oldest fossil followed by the upper layer's fossil and so on. The fossils present at the top layer are the youngest fossils so we can conclude that oldest fossils present at the bottom of rock layer whereas the youngest fossils are present in the top layer.
Learn more about rock layer here: brainly.com/question/14545004
Learn more: brainly.com/question/26122512
 
        
             
        
        
        
Answer: 
Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock. Obsidian is produced when felsic lava extruded from a volcano cools rapidly with minimal crystal growth. ... The inhibition of atomic diffusion through this highly viscous lava explains the lack of crystal growth.
 
        
             
        
        
        
Answer:
Gene Mutation and Chromosomal Mutation