Natural Selection and Genetics:🔬🧬#3
- Sharayu Salve
- 6 days ago
- 4 min read
Updated: 5 days ago
Why Your DNA Isn’t Just Sitting There. Ever wonder why some traits pop up more often in nature, like how every other person seems to have blue eyes, or how certain animals are always better at surviving than others?
🤔 It’s like a genetic popularity contest. But here’s the kicker—only the best genes make it to the next round🙌🏻. Natural selection isn’t just a vague “survival of the fittest”💪🏻 idea; it’s driven by the genetic variations we inherit. Yes, it’s all about what’s passed down through generations. And trust me, it’s not random!😉
☺️If you’ve been following along with our blog series, you already know that mutations are the starting point for this genetic diversity. Mutations give us those tiny variations in DNA, but it's natural selection that decides which ones stick around and shape the future of species. So, let’s dig in and see how this process works—and how it’s all tied back to the little genetic quirks that make us who we are.🤌🏻
---
What Is Natural Selection (Genetics-Style)?
Natural selection is the process by which traits that help an organism survive and reproduce become more common in a population over generations. In simpler terms, nature selects the traits that are most beneficial for survival. And those traits are encoded in genes—yes, 😀the DNA you inherited from your parents.
But don’t be fooled🤫; natural selection isn’t some random lottery. It’s driven by fitness—that is, how well an organism’s traits allow it to survive and reproduce in its environment. If a mutation makes an organism better suited for its environment, it's more likely to survive and pass on those beneficial genes. Over time, this process changes the genetic makeup of populations.
🧬🔬Genes, Traits, and Fitness
Now here’s where it gets personal. Think of fitness as your DNA's ability to get things done. Not necessarily about running a marathon or lifting weights (although that helps in some cases!), but about being able to thrive in your environment.
Take the sickle cell anemia gene, for example. In a non-sickled form, red blood cells carry oxygen throughout the body. But when a mutation causes the cells to become sickle-shaped, it can block blood flow and cause pain. Here’s the twist, though: people with just one copy of the sickle cell gene are actually more resistant to malaria. So, in areas where malaria is common, this mutation becomes beneficial. It’s a prime example of how genetics and natural selection work together—what starts as a random change becomes an evolutionary asset.
Real-Life Examples
1. Antibiotic Resistance in Bacteria
Ever heard of “superbugs”? Well, that’s an example of natural selection in action. When bacteria are exposed to antibiotics, some may have mutations that make them resistant. These resistant bacteria survive the treatment, multiply, and pass on their resistant genes. Over time, the population becomes more resistant to antibiotics.
2. Skin Color and UV Exposure
Humans have adapted to different climates in fascinating ways. Take skin color, for example. People from regions with more sunlight tend to have darker skin because the melanin protects against UV rays. Meanwhile, people from places with less sun tend to have lighter skin, which helps them absorb more vitamin D. It’s all about what genes help the population survive in its environment.
3. Lactose Tolerance in Humans
Another example? Lactase persistence (the ability to digest lactose after infancy). A mutation allowed some humans to keep producing lactase into adulthood, making it possible to digest milk. In populations that relied on dairy products, this mutation became advantageous. Now, that genetic trait is common in populations where dairy farming was a cultural norm.
Why It Matters in Evolution
You might be thinking, “Okay, this is cool and all, but why does it really matter in evolution?” Well, natural selection doesn’t just tweak a species here and there—it drives evolution. It’s the reason species adapt to their environment over generations. Mutations introduce genetic variety, and natural selection acts as the filter, shaping which genes will be passed on and which ones will fade out.
Think of it as a game of genetic survival. The more a trait helps survival, the more likely it is to be passed down. And over time, these tiny genetic shifts can lead to huge changes in a species. From bacteria becoming resistant to antibiotics, to humans evolving to thrive in different climates, natural selection is constantly shaping life on Earth.
That's it for today -
So, next time someone tells you “it’s in my genes,”😉 now you’ll know exactly what they mean—and maybe even explain it to them in more detail than they expected! Because, remember, it’s not just about traits—it’s about how natural selection molds those traits to help organisms survive.
Stay tuned for the next blog, where we’ll explore genetic drift and how random events can also change the genetic landscape. It’s all about the unexpected in evolution.
Sources:
Comentários