Tag Archives: development

Making sense of genotype-phenotype distinctions, version 3

Two foundational developments of modern biology—the theories of evolution by natural selection and the genetic basis of heredity—were built from the language, arguments, evidence, and practices of controlled breeding in agriculture and the laboratory.   The genotype-phenotype distinction—or, rather, a series of different meanings of those terms—provides an entry point into the implications of that genesis and subsequent developments. Complexities get suppressed, which engenders new problems and complexity-recovering responses. Many of these are raised or implied by Johannsen (1911), where the terms genotype and phenotype were introduced to English-language readers. Continue reading

His nature, her nurture-or what good are conceptual critiques for tackling practical concerns about the development of gendered individuals

This 23-minute youtube video is a practice run of a talk with the following abstract:

How difficult is it to change the typical distributions of a trait, such as aggression, substance abuse, suicide attempts, as they differ between males and females? This can be construed as a matter of fixity versus flexibility in the development of traits in individuals over their life course or of the relative degrees of hereditary versus environmental influences on the variation between versus within groups. This paper contrasts the conceptual critiques of research of the two construals with a view to clarifying how they address practical concerns about the development of gendered individuals, as raised especially by feminist scholars. Drawing on my book, Nature-Nurture? No (2014), I argue that inattention to heterogeneity has limited critique as well as research under both construals.

The three take home messages are that: conceptual critique (of the forms I describe) clears space for focusing on the development of gendered individuals; this counters a persistent essentialism about gender; and these first two messages have implications well beyond issues raised by feminist scholars.

See http://bit.ly/ishpssb15 for text of talk and references

What has Nature vs. Nurture got to do with Nature vs. Nurture? III

previous post considered the connection between two different Nature-Nurture issues: the matter of fixity versus flexibility in the development of traits in individuals over their life course and the relative degrees of hereditary versus environmental influences on the variation of the trait between versus within groups? (“Groups” here refers to males or females, but the question might be extended to socially defined racial or socio-economic groups.)  Continue reading

50 whys to look for genes: 29. Mental illness–Interaction of “genetic risk” with many environmental factors for behavioral traits

Kendler and colleagues examine behavioral traits in relation to a wealth of environmental factors over the life course as well as to the relatedness of the individuals (Kendler and Prescott 2006). In Kendler et al. (2002), for example, data on over 1,900 twins are used to fit the incidence of major depression to an additive model that incorporates many environmental factors and a “genetic risk” factor. This last factor is derived from the incidence of major depression in the co-twin and parents, with adjustments made for the degree of relatedness of the twins (monozygotic versus dizygotic). The model accounts for 52% of the variance in the trait and provides a picture of development that is rich and plausible (see figure below).

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Nature vs Nurture versus Nature and Nurture: A sketch of the history of the study of heredity, development, and variation

Why nature versus nurture? Surely it must be nature and nurture—we all know that traits develop over time through the interaction of the organism with genetic or hereditary and environmental or social influences. Indeed, the modern science of epigenetics, building on ever-increasing information about DNA sequences and how genes function, now shows us how chemicals from outside the cell can modify the activity of genes for the rest of an organism’s life and sometimes even into subsequent generations. Moreover, since the late 1800s—well before advances in molecular biology—developmental biologists have been studying the mechanisms through which a single cell divides into multiple cell types and gets arranged into tissues, organs, and the organism’s overall form (Gilbert 2013). The nature versus nurture in this book [Taylor 2014] is not, however, a matter of development of traits over time. A sketch of the history and current state of the study of heredity, development, and variation is needed to set the scene.

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Contradictions in valuing environmental services (Day 16 of Learning road trip)

Various groups co-sponsored a presentation by my road trip co-driver, Raúl García Barrios, on his various ecological and social restoration and conservation projects around Cuernavaca, México.  My role was to lead a 30-minute discussion.

The contradiction referred to in the title has three main parts:

  1. the monetary value that can be placed on ecosystem services in some of the watersheds near Cuernavaca is 1000 times less than the value that would follow from proposed housing developments (and freeways to serve those developments);
  2. the campaign to preserve the undeveloped system might succeed by appealing to legal and constitutional procedures (“defending the wall”), not market comparisons (i.e., economic valuations);
  3. the high economic values for development are based on government subsidies for home buyers and on a bubble, so blocking development is also a chance to save people from suffering when the bubble bursts, as it would eventually do.

The paper generated discussion on its own and I stepped back and let that happen.  However, as an experiment I had asked the audience to do a notecard exercise before the talk started, so I got them to do part 2 at the end.  The exercise was designed to explore how the audience view the three related questions (to follow) before versus after the presentation.

In a situation that concerns you:

  • what do you know?
  • what can be done on the basis of that knowledge?
  • what more do you need to inquire into in order to have the knowledge you need to see or show what is to be done.

Part 2 was to repeat this after the talk.

My review of the Before vs. After did not in most cases show the influence of the presentation, but the result was a rich set of issues that could be pursued in an environmental education curriculum, e.g.,

  • How to prioritize scale of response & target actors
  • Relationship between:  quest to understand complexity vs. need to act
  • Are there certain incentives that can increase good composting?
  • Look into financial structure of the tourism industry;  Tourism income doesn’t directly support conservation practices;  long term residents get little income
  • If sustainable development in subject to market rules, and thus to ethical and practical limitations therein, what are alternative pathways?
  • Low participation by minority students in environmental studies
  • Inquire into historical examples of defending the wall vs. state supported market forces
  • Delegitimation of state support for market

(back to Start of road trip; forward to later on Day 16)

Gender, Race, and the Complexities of Science and Technology: A bibliography

In a 2011 graduate course on “Gender, Race, and the Complexities of Science and Technology,” students were asked to add an annotated reference or resource (=person, organization…) to the evolving googledocs bibliography each week.  (Annotations were to convey the article’s key points as well as its connection to the student’s own inquiries and interests.)  The result is as follows: Continue reading