The independent variable is the type of available food.<span>The dependent variable is how often each beak type appears (or the count of birds possessing each beak type).</span>
Embryological evidence
Explanation:
Deuterostomes include echinoderms, hemichordates, and chordates. Despite their diverse body structures, they all feature a mouth that forms secondarily during embryonic development, thought to be a derived evolutionary trait connecting a common ancestor to all its descendants (a synapomorphy). This mouth originates from the ectoderm layer through invagination opposite the blastopore in the gastrula.
Initially, the scientist needs to determine the specific point in the Cretaceous period he wishes to investigate. This could involve studying the development of microorganisms from that era, the life cycle of a certain dinosaur species, or the evolution of dinosaurs, as well as the flora associated with that epoch, among other topics. This is referred to as the Observation phase of the scientific method.
Next, he will enter the phase known as "Hypothesis formulation" where he will pose inquiries relevant to his chosen study area. Questions might include, "How many flower types existed during that time?" and "Which of these flowers still exist today?" and so on.
Following this, he will proceed to the "Experimentation phase," where he will set up an experiment along with determining factors and variables crucial for answering the proposed hypotheses.
After conducting the experiment, data will be collected for analysis to generate results that address the previously established hypotheses. This step is termed "Data analysis."
Finally, he will reach the last step of the scientific method called "Conclusions," during which he will share the findings derived from the experiments.
