In line with my self-appointed mission of cleaning up the language of evolutionary science, I offer this.
The current issue of the Skeptic contains a chapter of a book about evolution. The author writes of “[Darwin’s] discovery of the theory of evolution by means of natural selection”. I submit that the correct description is “the theory of evolution by means of descent with random modification”.
I see the concept of “natural selection” as a purely physical layer atop something more fundamental and more important to the theory. Every inanimate and animate thing changes all the time (time == change). Some living individual things prosper more than others in their current environment. The physical earth-water-air-light environment of an individual living thing usually changes relatively slowly, but the living food-family-competitors environment of an individual living thing often changes quickly. Because an individual living thing’s DNA cannot change, individuals must die. These facts drive why living things must evolve or else disappear, but they are mostly independent of how living things evolve. Living lineages evolve (change) only through descent with modification, which Darwin saw and described clearly although without knowing the mechanisms.
Descent with modification has been completely random for billions of years: random flaws in protein replication, and random recombination of genes in sexual reproduction.
But humans can now carry out purposeful, directed evolution, for example by using CRISPR to wipe out malaria by genetically engineering the mosquitoes through which it spreads, or to wipe out Lyme disease by genetically engineering the rodents through which it spreads.
We are at a singularity. Now.
(I wrote this on a short-lived blog in 2010. It still represents my best shot at understanding what being alive on this planet means.)
What makes each of us emerge and grow and move and think?
The force of sunlight on spinning matter.
We are momentary patterns in the flow and ebb, warming and cooling, of water and soil under intense sunlight. You and I are massive colonies of bacteria heaved about daily by the sun. Bacteria are massive agglomerations of viruses and protein fragments. Viruses and proteins are not alive, but our bacteria are, and therefore we are.
There cannot be life without death. The world outside us is always changing. But none of us can change his/her internal pattern: once grown, each of us is essentially static as a genome. If we were each potentially immortal and had little or no drive to procreate, our species could not change, and we would die out under changing conditions. You and I are alive today because 400,000 generations of hominids and humans were driven to procreate. Each of our ancestors, randomly different from his/her parents and peers, happened to pass through the filters of natural selection that existed at that moment.
The sun drives us. Circumstances filter us. We need no conscious desire to adapt or change, and we have none within our physical beings. Change is forced on our species and every other species. Only a few lineages survive the filters.
How much do you know about your father’s mother’s mother? Probably almost nothing. How much of her is within you? Probably not much. Human patterns shimmer and evaporate in tiny fragments of time. Let us celebrate this.
Bernard, This New York Times article, Meet Luca, the Ancestor of All Living Things, exemplifies what I see as wrong-way thinking about evolution, thinking that directly or indirectly attributes purpose and foresight to evolution. Below are examples of what it says as opposed to what I believe it should say. Added text looks like this, deleted text. The article says: A surprisingly specific genetic portrait of the ancestor of all living things has been generated by scientists…
- I maintain it should say: A surprisingly specific genetic portrait of a proposed ancestor of all living things has been generated by scientists…
- Comment: Is it absolutely certain that change and natural selection didn’t winnow down more complex microbes, filtering out unused genetic material, resulting in what looks like an ancestor but is actually a residue?
I saw that interesting report too. The researchers applied powerful tools to uncover what genes might have been those of the now long extinct Last Common Ancestor of all living things, LUCA. All knowledgeable scientists, and me too, agree with you that evolution has no purpose or goal to achieve. The fancy way to say this is that it is not teleological. The sources of modification to any creature’s genome are random, and their direction is random. Some of these changes produce changes to the reproductive fitness of that organism in its particular environment, leading to the increase of the fraction of the population with those particular changes. But natural selection is not the only mechanism that leads to changes in a population’s genome. Research in recent decades has shown that random drift in a population the result of genomic changes that are either neutral with respect to natural selection or not exposed to natural selection are important sources of genomic and species change. Continue reading
Here’s my darling wife’s new grandson, Luke.
She’s gorgeous, and the little boy, just a few hours old is cute too.
I like his stylish cap.
I’m an honorary step grand dad, and I am grateful to her children for welcoming me.
This Google blog entry nicely summarizes what happened when a computer beat a world-champion Go player 4 games to 1 last month: “…while the match has been widely billed as ‘man vs. machine,’ AlphaGo is really a human achievement. [Korean champion] Lee Sedol and the AlphaGo team both pushed each other toward new ideas, opportunities and solutions…”. The outcome surprised many or most Go players and artificial intelligence (AI) people, coming perhaps even decades sooner than expected.
(For context, I play but not strongly, best-ever rank maybe 6 or 7 kyu. Wikipedia has a good article about the game. In chess you kill the opposing king, but in Go you only need to carve out more market share than your opponent.)
AlphaGo remembers, reasons (applies logic) and learns. But does AlphaGo think? Does it exhibit intelligence? And what does its victory say about artificial intelligence? I answer yes, yes, and some but not much.
Makes me go ballistic every time (says my wife) – here’s another example of anthropomorphic description of how evolution seems to have a purpose, in the sense of proactive adaptation (“driving”) versus what I claim MUST be viewed as passive filtering by an always-changing environment.
Through random mutation, evolution is relentlessly tinkering with the animal body plan, driving species toward diversification and various modes of living.
And this from the Skeptic! No, evolution is a result and not a cause. The cause is always the simplest conceivable cause that could exist: change. Time is change, change is time, that is all we know and all we need to know to understand evolution. The sentence should read something like this:
Through never-ending change in the external environment – some of which life feeds back into, for example a growing reef newly shading the bottom beside it – species thrive or fail according to how well they happen to fit today’s conditions and how well their offspring, randomly mutated, happen to fit tomorrow’s evolving conditions. Environmental changes filter changes in species.
Do I make sense? Does it matter? Clearly I think it does…
I think that the following, from this recent eSkeptic discussion, is not completely correct: “…reproduction is an absolutely essential component of any definition of life.” By this measure almost every instance of a living, breathing female mule and her male mule consort are not alive, since they cannot reproduce. From Wikipedia: “Mules and hinnies have 63 chromosomes, a mixture of the horse’s 64 and the donkey’s 62. The different structure and number usually prevents the chromosomes from pairing up properly and creating successful embryos, rendering most mules infertile. … As of October 2002, there had been only 60 documented cases of mules birthing foals since 1527.” Continue reading